EL3621-0020 | BECKHOFF | Terminal EtherCAT

Description

Processing high-accuracy current measurements in industrial environments is executed with precision using the Beckhoff EL3621-0020 EtherCAT Terminal. This single-channel differential analog input module handles signal levels from 4 to 20 mA with a highly detailed 24-bit resolution. Each terminal is factory-calibrated, offering an exceptional measuring error margin of less than +/-0.01 % at 25 degC. Operating directly on the EtherCAT I/O system, it bridges the gap between field sensors and centralized controllers with reliable E-bus communication.

Features

• High-Resolution Analog Digitization: Utilizes 24-bit digital signal conversion (including sign) for highly detailed process values.
• Factory Calibrated: Supplied with an official analog calibration certificate to ensure traceable measurement accuracy.
• Integrated Low-Pass Filtering: Hardware features an input filter limit frequency of 3 kHz, coupled with configurable conversion times from 1 ms to 400 ms.
• Differential Measurement Architecture: Features high common-mode voltage rejection up to a maximum of 10 V.
• Compact DIN-Rail Housing: Ultra-slim 12 mm form factor minimizes control cabinet footprint.

Applications

• Process technology loop-monitoring (flow, level, pressure, and temperature transmitters).
• High-precision test rigs and calibration benches requiring traceable laboratory-grade field metrics.
• Automated environmental logging stations and chemical dosing systems.

Technical Specifications

Connections and Interfaces

Empirical Engineering Insights

Alternative Models & Compatibility

The module provides a factory-calibrated alternative to standard analog inputs where sub-0.01 % accuracy is imperative. Please note that this terminal relies exclusively on the E-bus for power. It does not possess feed-through power contacts, so it must be factored into the overall E-bus current budget calculations when replacing standard, lower-consumption modules.

Application Pitfalls & Engineering Notes

Due to the 190 mA E-bus current consumption of this terminal, installing multiple high-precision modules side-by-side can quickly deplete the couplers feed capacity. Use an intermediate power supply terminal (such as the EL9410) if the total bus consumption exceeds the coupler rating. Avoid placing high-power switching relays immediately adjacent to this card to prevent EMI-induced drift in the 24-bit AD converter.

Commissioning & Wiring Tips

To achieve the factory-calibrated accuracy of less than 0.01 %, use shielded twisted-pair (STP) cabling for the 4 to 20 mA analog signal path. Ensure the cable shield is grounded at the entry point of the control panel. In TwinCAT 3, adjust the conversion filter settings to match the grid frequency (50 Hz or 60 Hz) to optimize common-mode noise rejection.

Installation Guidelines